NORDLUS Short presentation

Transcription

1 NORDLUS Short presentation Erik Vikingstad and Alert K. Imsland Akvaplan-niva

2 Development of Lumpfish Culture for Eco-friendly Biological Delousing of Atlantic Salmon (NORDLUS) Financed y NRC (BIP) and the Mait programme (Tromsø) Start-up April and Mai 2011 Partners Nordlaks (project responsile) Akvaplan-niva (co-ordinator) Gifas

3 Short on results in NORDLUS so far Successful juvenile production Mapping of temperature tolerance and optimum Behavioural studies (with salmon) in small scale Sea cage trials in small scale with promising results Alert K. Imsland, 4th Sea lice multination Trondheim 12th Novemer

4 Temperature tolerance and optimum Juvenile lumpfish grow very fast Roust juveniles, no mortality in temp. trials Large temperature tolerance range (4-16 C) Temperature optimum for growth etween 13 and 16 C for small juveniles and decreases with increasing size

5 Temperature optimum for lumpfish g g 5, = -0,216+0,6043*x-0,0203*x^2 3, = 1,2064+0,2871*x-0,0095*x^2 4,5 Opt. = 14,9 3,4 Opt. = 15,1 4,0 3,2 Vekst (%/dag) 3,5 3,0 2,5 Vekst (%/dag) 3,0 2,8 2,6 2,4 2,0 2,2 1, Temperatur (C) 2, Temperatur (C) g Opt g Opt Alert K. Imsland, 4th Sea lice multination Trondheim 12th Novemer

6 Trials with lumpfish in sea cages Juvenile lumpfish (c. 60 g) reared in 5x5x5 m sea cages with salmon ( kg) Three experimental groups: Control (without lumpfish) 10% mix of lumpfish (i.e. 120 salmon vs. 12 lumpfish in each cage) 15% mix of lumpfish (120 salmon vs. 18 lumpfish) All groups reared in replicates All lumpfish individually tagged Alert K. Imsland, 4th Sea lice multination Trondheim 12th Novemer

7 Alert K. Imsland, 4th Sea lice multination Trondheim 12th Novemer Materials and methods Sea lice were registered in five categories (Lepeophtheirus salmonis in four catagories chalimus, pre-adult, adult male, adult female amd Caligus elongatus) and infestation levels were analysed every other week for 54 days To determine the feed choices of lumpfish in the cages gastric lavage was performed every two weeks

8 Alert K. Imsland, 4th Sea lice multination Trondheim 12th Novemer Results Growth No differences in growth etween test groups and controls in either salmon or lumpfish were oserved Sea lice grazing Clear signs of lumpfish grazing of sea lice with significantly lower average numers of pre-adult, mature males and females stages of L. salmonis per salmon

9 Chalimus Levels of sea lice infestations, L. salmonis From day 38 onwards oth the 10% and 15% stocked cages showing less attached chalimus stages compared to the control cages

10 Average numer of Pre adult lice per fish Pre adults 1,20 1,00 control 10 % a 0,97 0,80 a 0,83 0,60 0,70 0,63 0,40 0,20 0,00 0,52 0,45 0,40 0,37 0,32 0,25 0,13 0, Numer of Days 0,50 Evidence of grazing from day 25 onwards Both lumpfish treatments had significantly less pre adults per fish compared to the control group at day 25 and 38 Both lumpfish treatments had 40% and 24% respectively less pre adults compared to the control cages at day 54

11 Average numer of Male lice per fish Mature males 0,90 0,80 control 10 % 15 % a a 0,70 0,60 0,75 0,77 a 0,50 0,52 0,40 0,30 0,20 0,43 0,28 0,30 0,22 0,22 0,23 0,10 0,00 0,02 0,07 0,05 0, Numer of Days Evidence of grazing from day 25 onwards 58% and 55% respectively less compared to the control group at day 54

12 Average numer of Female lice per fish Mature females 1,20 1,00 control 10 % 15 % a a 1,00 0,80 0,83 0,60 0,40 0,20 0,00 0,07 0,08 Clear evidence of grazing in oth treatments with average numers per fish recorded at day 54 eing 0.07 and 0.03 per fish At day 54, the 10% and 15% treatments had 93% and 97% less female lice compared to the control Control group: y day 38 had surpassed the set treatment threshold (average 0.83 per fish) a 0,18 0,05 0,00 0,03 0,03 0,10 0,08 0, Numer of Days 0,03

13 Sea lice: Caligus elongatus Evidence of grazing from gastric lavage Day 54, oth the 10% and 15% stocked cages had 25% and 42% less

14 Sampling time points Gastric lavage of lumpfish The proportion eating sea lice increases from 10 to 36% during the trial period But still 60% of lumpfish not eating lice Large individual differences in sea lice preferences % 29% 36% No differences etween 10 and 15% groups in lice preferences % 21% 0% 10% 20% 30% 40% Percentage of individuals with ingested sea lice

15 Frequency Gastric lavage The percentage frequency of food choices identified over all 291 individual gastric lavages 80% 75% 70% 60% 50% 40% 30% 27% 26% 27% 26% 24% 20% 10% 0% 7% Pellets Molluscs No contents Grey mass Crustaceans Hydrozoans Sea lice

16 Further trials in Sea lice preferences of different size groups of lumpfish Behavioural studies Large scale studies Broodstock development Genetic studies of sea lice preferences in different groups of lumpfish Alert K. Imsland, 4th Sea lice multination Trondheim 12th Novemer

17 Alert K. Imsland, Rensefisk workshop, Bergen 8. feruar Thank you for your attention